The present invention relates to an electric guitar with a tremolo unit.
An electric guitar that has a tremolo unit prevents the electric guitar from being detuned by changes in the tension (pitch) of strings while the guitar is being played using the tremolo unit. U.S. Pat. No. 4,171,661 discloses an electric guitar that has a tremolo unit. According to the guitar of the publication, each string is locked by a bolt and a presser member at a saddle of the tremolo unit. A fixing member is also arranged on a nut, which is located in the vicinity of the head, to fix the strings. This structure prevents the guitar to be detuned even if the tremolo unit is used.
FIG. 8 illustrates another type of tremolo unit. This tremolo unit has a base plate 23 and a hinge mechanism for connecting the base plate 23 to a guitar body. A pair of pin supports 61, 61 is integrally formed with the base plate 23 at the sides of the base plate 23. A bore 61a is formed in each pin support 61. A coupling pin 62 is connected to each pin support 61 by press fitting the proximal end of the pin 62 into the bore 61a. A pair of brackets 64, 64 is coupled to the body with support pins 63, 63. Each bracket 64 can pivot about the corresponding support pin 63. A bearing device comprising a single bearing 65 fits in each bracket 64. Each coupling pin 62 fits into the central bore of the corresponding bearing 65.
Since the coupling pins 62 receive relatively great tension of the strings, the bores 61a need to be sufficiently deep to bear the tension. Also, since the bearings 65, 65 receive the tension of the strings, the bearings 65 need to be sufficiently long to bear the tension. The distance D1 between the centers O1, O1 of the bores 61a, 61a and the distance between the center O1 of each bore 61a and the axial midpoint O2 of the corresponding bearing 65 are determined to ensure sufficient depth of the bores 61a and sufficient length of bearings 65
The distance D3 between the axial midpoint O2 of each bearing 65 (the corresponding midpoint O3) and the outer edge of the corresponding bracket 64 is determined such that the midpoint O3 of each support pin 63 is included in a line that contains the axial midpoint O2 of the corresponding bearing 65 and is parallel to the strings. Accordingly, the tension of the strings evenly acts on the bearings 65, 65. In this structure, the distance between the outer edges of the brackets 64, 64 is represented by a formula D1+2xc3x97D2+2xc3x97D3. The brackets 64 thus require a relatively large lateral space. If widely separated, the brackets 64 impair the appearance of the guitar.
Accordingly, it is an objective of the present invention to provide an electric guitar with a tremolo unit that minimizes the space required for a hinge mechanism supporting the base plate.
To achieve the foregoing and other objectives and in accordance with the purpose of the present invention, an electric guitar having a plurality of strings is provided. Each string has a first contact point defined on a neck and a second contact point defined on a base plate attached to a body. The guitar includes a hinge mechanism for supporting the base plate such that the base plate pivots relative to the body. The hinge mechanism includes a pair of bores, a pair of bearing devices, a pair of support pins, a pair of brackets, and a pair of bracket pins. Each bore is formed at a side of the base plate. Each bearing device is located in one of the bores. The support pins protrude from the body. Each support pin corresponds to one of the bearing devices and is located closer to the neck than the corresponding bearing device. Each bracket is coupled to one of the support pins. Each bracket pin is coupled to one of the brackets and fits into the corresponding bearing device. The axial midpoint of each bearing device and the center of the corresponding support pin are located on a line that is substantially parallel to the strings.
Other aspects and advantages of the invention will become apparent from the following description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the invention.